Semi-Hermetic Two-stage Reciprocating Refrigeration Compressor Unit

Engineered to meet the evolving demands of modern refrigeration and air conditioning systems, the Semi-Hermetic Two-stage Reciprocating Refrigeration Compressor Unit supports the use of environmentally responsible refrigerants including R290 (propane) and other eco-friendly alternatives, positioning it as a future-ready solution aligned with global environmental regulations and the ongoing phase-down of high-GWP refrigerants. Whether serving the precise cooling requirements of a state-of-the-art commercial facility or the robust industrial demands of a large-scale cold chain operation, the SP Series delivers the reliability, efficiency, and operational flexibility that today's applications demand.

Available Configurations

Application

The SP Series Semi-Hermetic Two-stage Reciprocating Refrigeration Compressor Unit is designed to serve a broad range of refrigeration and air conditioning applications across commercial and industrial sectors:

● Commercial Refrigeration: Supermarkets, convenience stores, food retail display cases, walk-in coolers and freezers

● Industrial Refrigeration: Food processing plants, cold storage warehouses, blast freezing facilities

● Air Conditioning Systems: Commercial HVAC, rooftop package units, precision cooling for data centers and clean rooms

● Food & Beverage Industry: Breweries, dairy processing, beverage chilling, and perishable goods preservation

● Pharmaceutical & Healthcare: Temperature-controlled storage for medicines, vaccines, and biological materials

● Hospitality & Retail: Hotels, restaurants, catering facilities, and shopping centers

● Transportation Refrigeration: Refrigerated transport and logistics cooling infrastructure

● Environmental & Green Building Projects: Energy-efficient cooling solutions for LEED-certified and low-carbon buildings

What are the technical features of this product?

① High Working Pressure — Up to 28 Bar

We designed the SP Series to handle a maximum working pressure of up to 28 bar, giving it the strength and reliability required for demanding refrigeration systems. Whether you’re working with different refrigerants or operating in medium- to low-temperature environments, our compressors maintain stable and efficient performance.

This higher pressure capability doesn’t just improve durability — it gives you more freedom in system design, helping you meet complex application requirements without sacrificing safety or structural integrity.

② Highly Integrated Compact Design

One of the key features of our Semi-Hermetic Two-stage Reciprocating Refrigeration Compressor Unit is its integrated architecture. The compressor body directly integrates the filter, service shut-off valve, and temperature sensor, eliminating the need for separate external components and simplifying the piping layout of the entire system. Despite this high level of integration, the SP series compressors maintain an extremely compact overall size, facilitating installation in space-constrained equipment rooms and reducing system installation time and costs.

③ RefComp-Designed Crankshaft with Counterweights

The SP Series features a proprietary crankshaft design developed by RefComp, engineered with precision-balanced counterweights to dynamically offset the reciprocating forces generated during compression. This careful dynamic balancing results in exceptionally smooth operation with minimal vibration, reducing mechanical stress on connected piping and structural supports, extending bearing and seal life, and contributing to a quieter operational environment.

④ High Efficiency, High Strength, Low Vibration & Low Noise

It is designed to deliver an optimal combination of high volumetric and isentropic efficiency, ensuring maximum refrigerating capacity per unit of power consumed. The use of high-strength materials throughout the compressor assembly ensures structural robustness under cyclic pressure loads, while the carefully optimized valve geometry and gas passage design minimize pressure pulsation, gas flow noise, and mechanical vibration — resulting in a quieter, smoother operating compressor that is well-suited to noise-sensitive installations.

⑤ Flexible Capacity Modulation

The product supports flexible capacity selection and adjustment to match varying load demands. Operators can select the appropriate cylinder count configuration to suit the nominal system load, and further fine-tune cooling output through capacity modulation options. This flexibility allows precise matching of refrigeration capacity to actual demand, avoiding energy waste associated with oversized compressors running at reduced efficiency, and enabling superior part-load performance in applications with fluctuating cooling loads.

⑥ Integrated Motor Protection Module

Each Semi-Hermetic Two-stage Reciprocating Refrigeration Compressor Unit is equipped with a dedicated motor protection module that continuously monitors critical electrical and thermal parameters. The module provides protection against over-current, over-temperature, phase loss, phase reversal, and other fault conditions that could damage the motor windings or reduce compressor service life. This built-in safeguard minimizes the risk of unexpected downtime, reduces the need for external protection relay equipment, and simplifies the electrical control panel design.

⑦ Internal Pressure Relief Valve — High/Low Side Equalization

This product features incorporates a built-in internal equalizing valve connecting the high-pressure and low-pressure sides of the compressor. This valve automatically activates to prevent internal pressure from exceeding safe limits, protecting the compressor body, valve plates, and pistons from overpressure damage. This feature is particularly valuable during start-up after extended shutdown periods and in systems subject to rapid load fluctuations, providing an additional layer of protection without the need for external safety devices.

⑧ Innovative Suction Gas Motor Cooling Design

The SP Series employs a specially engineered structural layout that routes refrigerant gas from the suction shut-off valve directly through the motor housing before entering the compression cylinders. This design leverages the cool, low-pressure suction gas to continuously cool the motor windings, preventing overheating under sustained high-load operation and eliminating the need for additional external motor cooling systems. This suction-gas-cooled motor configuration enhances motor reliability, extends winding insulation life, and contributes to the compressor's overall energy efficiency.

Refrigerant Compatibility & Environmental Responsibility

The SP Series has been designed with forward-looking refrigerant compatibility as a core engineering objective. In addition to conventional HFC refrigerants, the SP Series fully supports operation with R290 (propane) — a natural hydrocarbon refrigerant with an ultra-low Global Warming Potential (GWP = 3) and zero Ozone Depletion Potential (ODP = 0). This makes the SP Series an ideal platform for manufacturers and system integrators seeking to comply with F-Gas regulations, the Kigali Amendment to the Montreal Protocol, and other international environmental standards driving the transition to low-GWP refrigerants.

Key Technical Specifications

Why Choose the SP Series?

· Proven Reliability: Designed and validated to deliver consistent performance across tens of thousands of hours of operation in real-world commercial and industrial environments.

· Environmental Leadership: Native support for R290 and other low-GWP refrigerants ensures regulatory compliance today and into the future.

· Simplified Installation: The integrated, compact design reduces on-site assembly time, minimizes field piping, and lowers overall installation costs.

· Operational Flexibility: With 34 models spanning 3 to 70 HP, the Semi-Hermetic Two-stage Reciprocating Refrigeration Compressor Unit provides the right compressor for virtually every commercial and industrial refrigeration requirement.

· Energy Efficiency: Advanced crankshaft design, optimized valve geometry, and suction gas motor cooling combine to deliver industry-leading efficiency across the full operating range.

· Reduced Maintenance: High-quality materials, balanced rotating components, and integrated protection systems work together to minimize wear, reduce fault rates, and extend service intervals.